How is [x] used in medieval German?

[Koen G]

All of these examples are euphemisms, where the speaker prefers a 'lite' version compared to the full-blown swear word.

Yes, but we are looking at two different types of euphemisms, and I haven't worked out yet which one it is.

1) "pock", a male goat, as a euphemism for the devil. In this case, they believed that speaking the name of the devil would bring evil, so they used a different, existing word to describe him. A similar practice would be to say "passed away" instead of "died". You just use different, existing words as a euphemism for the word to be avoided.

2) "pox" as a minced form of Gotts. This would be the equivalent of the potverdorie case, which as you point out is rather similar. This is different from the case above, as "pot" is not a way to describe God, it just sounds similar.


Now one thing I should point out is that "poxleber" is not an isolated swearword, it's not like people yelled out "poxleber!" when they hit their thumb with a hammer. Instead, the phrase is always something like:

"May pox something cause you harm".

May pox liver hurt you. May pox five wounds do something unpleasant to you. May pox blood do something. May pox body do something to you. 

In most of these cases, it does seem clear that God is intended and not the Devil: the five wounds of Jesus, his blood, his body. Not sure about the liver though. Note that the phrase on You are not allowed to view links. Register or Login to view. does not seem to point towards the standard type of phrase in which the expletive form of pox is used.

Still, I must say that I was almost ready to commit to the "expletive" theory, since it looked like genitives written with -x were impossible to find. However, in the second database I browsed I found "spex", the genitive of "speck". And I somehow missed that an example of "poxleber" from a cookbook exists in the pdf you linked above.

All of the examples we are dealing with are rare in the 15th century. People were unlikely to take the Lord's name in vain in their writing, even a minced form. People were still genuinely afraid of the devil. It makes sense that examples of the written expletive only start occurring slightly later, in texts of plays for example, to reflect a certain character's way of speaking. And for goat's liver, it appears that scribes did not often replace genitives ending in /ks/ with "x", so these examples are also rare.